xref: /XiangShan/src/main/scala/xiangshan/backend/fu/vector/VFPU.scala (revision e81c273d4f5649259d24573c1911df9885580de6)
1/****************************************************************************************
2  * Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3  * Copyright (c) 2020-2021 Peng Cheng Laboratory
4  *
5  * XiangShan is licensed under Mulan PSL v2.
6  * You can use this software according to the terms and conditions of the Mulan PSL v2.
7  * You may obtain a copy of Mulan PSL v2 at:
8  *          http://license.coscl.org.cn/MulanPSL2
9  *
10  * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11  * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12  * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13  *
14  * See the Mulan PSL v2 for more details.
15  ****************************************************************************************
16  */
17
18
19package xiangshan.backend.fu.vector
20
21import chipsalliance.rocketchip.config.Parameters
22import chisel3.{Mux, _}
23import chisel3.util._
24import utils._
25import utility._
26import yunsuan.vector.{VectorFloatAdder,VectorFloatFMA,VectorFloatDivider}
27import yunsuan.VfpuType
28import xiangshan.{FuType, XSCoreParamsKey}
29
30class VFPU(implicit p: Parameters) extends VPUSubModule(p(XSCoreParamsKey).VLEN) {
31  XSError(io.in.valid && io.in.bits.uop.ctrl.fuOpType === VfpuType.dummy, "VFPU OpType not supported")
32  XSError(io.in.valid && (io.in.bits.uop.ctrl.vconfig.vtype.vsew === 0.U), "8 bits not supported in VFPU")
33  override val dataModule = Seq(
34    Module(new VfaluWrapper),
35    Module(new VfmaccWrapper),
36    Module(new VfdivWrapper)
37  )
38  val select0 = io.in.bits.uop.ctrl.fuOpType === VfpuType.isVfalu
39  val select1 = io.in.bits.uop.ctrl.fuOpType === VfpuType.isVfmacc
40  val select2 = io.in.bits.uop.ctrl.fuOpType === VfpuType.isVfdiv
41  override val select = Seq(
42    io.in.bits.uop.ctrl.fuType === FuType.vfpu && select0,
43    io.in.bits.uop.ctrl.fuType === FuType.vfpu && select1,
44    io.in.bits.uop.ctrl.fuType === FuType.vfpu && select2
45  )
46  connectDataModule
47}
48
49class VfdivWrapper(implicit p: Parameters)  extends VPUDataModule{
50  needReverse := false.B
51  needClearMask := false.B
52
53  val Latency = List(5, 7, 12)
54  val AdderWidth = XLEN
55  val NumAdder = VLEN / XLEN
56
57  // TODO: Place these logic within the functional unit
58  val inHs = io.in.fire()
59  val s0_mask = DataHoldBypass(in.src(3), inHs)
60  val s0_sew = DataHoldBypass(in.uop.ctrl.vconfig.vtype.vsew(1,0), inHs)
61  val s0_vl = DataHoldBypass(in.uop.ctrl.vconfig.vl, inHs)
62
63  val vfdiv = Seq.fill(NumAdder)(Module(new VectorFloatDivider()))
64  for (i <- 0 until NumAdder) {
65    vfdiv(i).io.opb_i := Mux(inHs, vs1(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
66    vfdiv(i).io.opa_i := Mux(inHs, vs2(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
67    vfdiv(i).io.is_vec_i := true.B // If you can enter, it must be vector
68    vfdiv(i).io.frs2_i    := in.src(0)(63,0) // f[rs2]
69    vfdiv(i).io.frs1_i    := in.src(1)(63,0) // f[rs1]
70    vfdiv(i).io.is_frs1_i := false.B // if true, vs2 / f[rs1]
71    vfdiv(i).io.is_frs2_i := false.B // if true, f[rs2] / vs1
72    vfdiv(i).io.is_sqrt_i := false.B // must false, not support sqrt now
73    vfdiv(i).io.rm_i := rm
74    vfdiv(i).io.fp_format_i := Mux(inHs, in.uop.ctrl.vconfig.vtype.vsew(1,0), 3.U(2.W))
75    vfdiv(i).io.start_valid_i := io.in.valid
76    vfdiv(i).io.finish_ready_i := io.out.ready
77    vfdiv(i).io.flush_i := false.B  // TODO
78  }
79
80  val s4_fflagsVec = VecInit(vfdiv.map(_.io.fflags_o)).asUInt()
81  val s4_fflags16vl = fflagsGen(s0_mask, s4_fflagsVec, List.range(0, 8))
82  val s4_fflags32vl = fflagsGen(s0_mask, s4_fflagsVec, List(0, 1, 4, 5))
83  val s4_fflags64vl = fflagsGen(s0_mask, s4_fflagsVec, List(0, 4))
84  val s4_fflags = LookupTree(s0_sew(1, 0), List(
85    "b01".U -> Mux(s0_vl.orR, s4_fflags16vl(s0_vl - 1.U), 0.U(5.W)),
86    "b10".U -> Mux(s0_vl.orR, s4_fflags32vl(s0_vl - 1.U), 0.U(5.W)),
87    "b11".U -> Mux(s0_vl.orR, s4_fflags64vl(s0_vl - 1.U), 0.U(5.W)),
88  ))
89  val s4_result = VecInit(vfdiv.map(_.io.fpdiv_res_o)).asUInt()
90
91  io.out.bits.data := s4_result
92  fflags := s4_fflags
93  io.in.ready := VecInit(vfdiv.map(_.io.start_ready_o)).asUInt().andR()
94  io.out.valid := VecInit(vfdiv.map(_.io.finish_valid_o)).asUInt().andR()
95}
96
97class VfmaccWrapper(implicit p: Parameters)  extends VPUDataModule{
98  needReverse := false.B
99  needClearMask := false.B
100
101  val Latency = 3
102  val AdderWidth = XLEN
103  val NumAdder = VLEN / XLEN
104
105  val inHs = io.in.fire()
106
107  val validPipe = Seq.fill(Latency)(RegInit(false.B))
108  validPipe.zipWithIndex.foreach {
109    case (valid, idx) =>
110      val _valid = if (idx == 0) Mux(inHs, true.B, false.B) else validPipe(idx - 1)
111      valid := _valid
112  }
113  // TODO: Place these logic within the functional unit
114  val s0_mask = DataHoldBypass(in.src(3), inHs)
115  val s0_sew = DataHoldBypass(in.uop.ctrl.vconfig.vtype.vsew(1, 0), inHs)
116  val s0_vl = DataHoldBypass(in.uop.ctrl.vconfig.vl, inHs)
117
118  val vfmacc = Seq.fill(NumAdder)(Module(new VectorFloatFMA()))
119  for (i <- 0 until NumAdder) {
120    vfmacc(i).io.fp_a := Mux(inHs, vs1(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
121    vfmacc(i).io.fp_b := Mux(inHs, vs2(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
122    vfmacc(i).io.fp_c := Mux(inHs, in.src(2)(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
123    vfmacc(i).io.widen_b := Mux(inHs, Cat(vs1((AdderWidth / 2) * (i + 3) - 1, (AdderWidth / 2) * (i + 2)), vs1((AdderWidth / 2) * (i + 1) - 1, (AdderWidth / 2) * i)), 0.U)
124    vfmacc(i).io.widen_a := Mux(inHs, Cat(vs2((AdderWidth / 2) * (i + 3) - 1, (AdderWidth / 2) * (i + 2)), vs2((AdderWidth / 2) * (i + 1) - 1, (AdderWidth / 2) * i)), 0.U)
125    vfmacc(i).io.frs1 := in.src(0)(63,0)
126    vfmacc(i).io.is_frs1 := false.B // TODO: support vf inst
127    vfmacc(i).io.uop_idx := in.uop.ctrl.uopIdx // TODO
128    vfmacc(i).io.op_code := DontCare // TODO
129    vfmacc(i).io.is_vec := true.B // If you can enter, it must be vector
130    vfmacc(i).io.round_mode := rm
131    vfmacc(i).io.fp_format := Mux(inHs, in.uop.ctrl.vconfig.vtype.vsew(1,0), 3.U(2.W))
132    vfmacc(i).io.res_widening := false.B // TODO
133  }
134
135  // output signal generation
136  val s2_fflagsVec = VecInit(vfmacc.map(_.io.fflags)).asUInt()
137  val s2_fflags16vl = fflagsGen(s0_mask, s2_fflagsVec, List.range(0, 8))
138  val s2_fflags32vl = fflagsGen(s0_mask, s2_fflagsVec, List(0, 1, 4, 5))
139  val s2_fflags64vl = fflagsGen(s0_mask, s2_fflagsVec, List(0, 4))
140  val s2_fflags = LookupTree(s0_sew(1, 0), List(
141    "b01".U -> Mux(s0_vl.orR, s2_fflags16vl(s0_vl - 1.U), 0.U(5.W)),
142    "b10".U -> Mux(s0_vl.orR, s2_fflags32vl(s0_vl - 1.U), 0.U(5.W)),
143    "b11".U -> Mux(s0_vl.orR, s2_fflags64vl(s0_vl - 1.U), 0.U(5.W)),
144  ))
145
146  val s2_result = VecInit(vfmacc.map(_.io.fp_result)).asUInt()
147
148  io.out.bits.data := s2_result
149  fflags := s2_fflags
150
151  io.in.ready := true.B
152  io.out.valid := validPipe(Latency - 1)
153}
154
155class VfaluWrapper(implicit p: Parameters)  extends VPUDataModule{
156  needReverse := false.B
157  needClearMask := false.B
158
159  val Latency = 2
160  val AdderWidth = XLEN
161  val NumAdder = VLEN / XLEN
162
163  val inHs = io.in.fire()
164
165  // reg input signal
166  val validPipe = Seq.fill(Latency)(RegInit(false.B))
167  validPipe.zipWithIndex.foreach {
168    case (valid, idx) =>
169      val _valid = if (idx == 0) Mux(inHs, true.B, false.B) else validPipe(idx - 1)
170      valid := _valid
171  }
172  // TODO: Place these logic within the functional unit
173  val s0_mask = DataHoldBypass(in.src(3), inHs)
174  val s0_sew = DataHoldBypass(in.uop.ctrl.vconfig.vtype.vsew(1, 0), inHs)
175  val s0_vl = DataHoldBypass(in.uop.ctrl.vconfig.vl, inHs)
176
177  // connect the input signal
178  val vfalu = Seq.fill(NumAdder)(Module(new VectorFloatAdder()))
179  for (i <- 0 until NumAdder) {
180    vfalu(i).io.fp_b := Mux(inHs, vs1(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
181    vfalu(i).io.fp_a := Mux(inHs, vs2(AdderWidth * (i + 1) - 1, AdderWidth * i), 0.U)
182    vfalu(i).io.widen_b := Mux(inHs, Cat(vs1((AdderWidth / 2) * (i + 3) - 1, (AdderWidth / 2) * (i + 2)), vs1((AdderWidth / 2) * (i + 1) - 1, (AdderWidth / 2) * i)), 0.U)
183    vfalu(i).io.widen_a := Mux(inHs, Cat(vs2((AdderWidth / 2) * (i + 3) - 1, (AdderWidth / 2) * (i + 2)), vs2((AdderWidth / 2) * (i + 1) - 1, (AdderWidth / 2) * i)), 0.U)
184    vfalu(i).io.frs1 := in.src(0)(63, 0)
185    vfalu(i).io.is_frs1 := false.B // TODO: support vf inst
186    vfalu(i).io.mask := 0.U //TODO
187    vfalu(i).io.uop_idx := in.uop.ctrl.uopIdx // TODO
188    vfalu(i).io.is_vec := true.B // If you can enter, it must be vector
189    vfalu(i).io.round_mode := rm
190    vfalu(i).io.fp_format := Mux(inHs, in.uop.ctrl.vconfig.vtype.vsew(1,0), 3.U(2.W))
191    vfalu(i).io.opb_widening := false.B // TODO
192    vfalu(i).io.res_widening := false.B // TODO
193    vfalu(i).io.op_code := in.uop.ctrl.fuOpType
194  }
195
196  // output signal generation
197  val s0_fflagsVec = VecInit(vfalu.map(_.io.fflags)).asUInt()
198  val s0_fflags16vl = fflagsGen(s0_mask, s0_fflagsVec, List.range(0, 8))
199  val s0_fflags32vl = fflagsGen(s0_mask, s0_fflagsVec, List(0, 1, 4, 5))
200  val s0_fflags64vl = fflagsGen(s0_mask, s0_fflagsVec, List(0, 4))
201  val s0_fflags = LookupTree(s0_sew(1, 0), List(
202    "b01".U -> Mux(s0_vl.orR, s0_fflags16vl(s0_vl - 1.U), 0.U(5.W)),
203    "b10".U -> Mux(s0_vl.orR, s0_fflags32vl(s0_vl - 1.U), 0.U(5.W)),
204    "b11".U -> Mux(s0_vl.orR, s0_fflags64vl(s0_vl - 1.U), 0.U(5.W)),
205  ))
206  val s1_fflags = RegEnable(s0_fflags, validPipe(Latency-2))
207  val s0_result = VecInit(vfalu.map(_.io.fp_result)).asUInt()
208  val s1_result = RegEnable(s0_result, validPipe(Latency-2))
209
210  fflags := s1_fflags
211  io.out.bits.data := s1_result
212
213  io.in.ready := true.B
214  io.out.valid := validPipe(Latency-1)
215}
216
217object fflagsGen{
218  def fflagsGen(vmask: UInt, fflagsResult:UInt, idx:List[Int] = List(0, 1, 4, 5)): Vec[UInt] = {
219    var num = idx.length
220    val fflags = Seq.fill(num)(Wire(UInt(5.W)))
221    fflags.zip(vmask(num-1, 0).asBools().reverse).zip(idx).foreach {
222      case ((fflags0, mask), id) =>
223        fflags0 := Mux(mask, fflagsResult(id*5+4,id*5+0), 0.U)
224    }
225    val fflagsVl = Wire(Vec(num,UInt(5.W)))
226    for (i <- 0 until num) {
227      val _fflags = if (i == 0) fflags(i) else (fflagsVl(i - 1) | fflags(i))
228      fflagsVl(i) := _fflags
229    }
230    fflagsVl
231  }
232
233  def apply(vmask: UInt, fflagsResult:UInt, idx:List[Int] = List(0, 1, 4, 5)): Vec[UInt] = {
234    fflagsGen(vmask, fflagsResult, idx)
235  }
236}